During the past year, our research group has devoted substantial effort to processing the diagnostic data, developing codebooks for the self-administered questionnaires, constructing secondary variables for analysis and preparing the papers describing the study design, methods and measures, and conducting analyses for the initial publications of the prevalence and services for adolescent mental disorders. The first paper (Merikangas et al. 2009) provides a summary of the context for development of the NCS-A, and a description of the measures of adolescents and their parents. There is convincing evidence that the NCS-A contains unparalleled information that can be used as the national estimates of prevalence and correlates of adolescent mental disorders, risk and protective factors, patterns of service use, and ethnic diversity in mental disorders and their treatment. The retrospective NCS-A data on development of psychopathology can additionally complement data from longitudinal studies based on more geographically restricted samples and serve as a useful baseline for future prospective studies of the onset and progression of mental disorders in adulthood. The NCS-A design and field procedures article (Kessler et al, 2009a,b) presented comparisons between the NCS-A sample and the school samples with respect to the population distributions on census socio-demographic variables. The results demonstrate that the NCS-A is an efficient sample of the target population with a good representation on a variety of socio-demographic and geographic variables. Our analyses of the clinical reappraisal study yielded good aggregate consistency between World Health Organization Composite International Diagnostic Interview (CIDI) and blinded clinical diagnoses using the Schedule for Affective Disorder and Schizophrenia for School-Age Children (K-SADS) and demonstrated that prevalence estimates based on the two instruments are fairly similar in substantive terms for most disorders, and that symptom-level modifications can be used to correct prevalence estimates in most cases where between-instrument differences in prevalence estimates are substantively meaningful. The results demonstrated that the CIDI has good concordance with clinician diagnoses, providing a solid foundation for later substantive analyses of the NCS-A data (Kessler et al, 2009c). We have also completed the first prevalence paper of the full range of diagnostic and statistical manual of mental disorders, fourth edition(DSM-IV) mental disorders in adolescents in the U.S. (Merikangas et al, under review). Estimates of twelve-month prevalence rates of mental disorders in adolescents are as follows: mood disorders, 12.5%;anxiety disorders, 24.9%;substance use disorders, 8.3%;behavior disorders, 14.1%;intermittent explosive disorder, 11.2%;and eating disorders, 2.8%. Approximately one-fifth of those youth with a twelve-month disorder had serious impairment. On average, lifetime prevalence rates were about 20% higher than the 12 month rates. Both the 12-month and lifetime prevalence rates were only slightly lower than those of adults in the National Comorbidity Survey-Replication, which applied the comparable methods for assessment and diagnosis. There was a substantial amount of co-occurrence of both 12-month and lifetime disorders, with only 23% of those with a lifetime disorder meeting criteria for only one disorder. Females had elevated rates of mood, anxiety and eating disorders, whereas behavior and substance use disorders were more common among males. Non-Hispanic black adolescents had significantly lower rates of substance use disorders and mood disorders, and Hispanic adolescents had higher rates of eating disorders compared to non-Hispanic whites. The most potent family contextual influence on adolescent mental health was the number of biologic parents in the household;youth with only one parent had a 1.8-fold increased rate, and those with no biologic parent had a 2.1-fold increased rate of mental disorders compared to those living with 2 biologic parents. Other family factors associated with adolescent mental disorders were lower parental education and larger sibship size. The manuscript is now ready for submission. We have recently completed the analyses of service patterns for mental disorders in U.S. adolescents in collaboration with Ronald Kessler, Ph.D. The proportion of youth with 12 month disorders receiving mental health services ranges from a high for Conduct Disorder (89.6%) to a low for Specific Phobia (59.8%). The treatment rate is higher in cases with severe disorder (Post Traumatic Stress Disorder) than those with mild (Specific Phobia). The more disorders one has, the more likely he gets a treatment. There is a dose-response between number of disorders and proportion of treatment. Most treatment occurred in the MH specialty sector, followed by school service. Within the Mental Health Specialty sector, the vast majority is in Outpatient care. We are in the process of preparing a manuscript reporting these findings in collaboration with Dr. Jane Costello of Duke University. We have begun to examine the spectrum concept of mood disorder using framework to characterize people with mania and/or depression. This work is being conducted with a team of international investigators (Jules Angst, M.D., Zurich, Switzerland, Petra Zimmerman, Ph.D., Munich, Germany) who propose to modify the current diagnostic nomenclature by considering bipolar disorder and major depression as a spectrum of symptoms, duration, recurrence, and severity rather than as discrete categories. Our analyses are designed to test the validity of the spectrum concept in a population-based adolescent sample using independent indices such as role impairment, family history, severity and patterns of comorbidity. We are organizing a collaborative cross national work group to examine race and ethnicity disparities and the effect of immigration on adolescent mental disorders. The other participating countries/parties include Mexico, Columbia, Taiwan, China, The National Survey of American Life (NSAL), The National Latino and Asian American Study (NLAAS). Public Health Impact: Aside from providing the first prevalence data on a nationally representative sample of U.S. adolescents, the results of this study demonstrate that adult mental disorders emerge in adolescence, with about one-fifth of those with a 12-month mental disorder already suffering from severe impairment. The most striking finding was the strong impact of non-intact households that was pervasive across all classes of mental disorders. Although this effect may reflect both biologic and contextual risk associated with parental mental disorders, future examination of potential mechanisms for this association both in this study and other prospective research on adolescents is imperative. These findings highlight the need for a shift of focus to prevention and early intervention to minimize the impact of mental disorders in U.S. youth. Future work on this rich resource will help to address the gap in national data on adolescent mental health, and the dramatic personal and societal impact of adolescent mental disorders. During the next year, we plan to conduct analyses of the prevalence and correlates of mood and anxiety disorders, to examine patterns of comorbidity between mental and physical disorders, especially the association of mood and anxiety disorders with migraine and sleep disorders. We will complete the salivary stress hormone assays and evaluate their association with mental disorders in adolescents.